/
Chapter 1
Save to my account
Sign up
Chapter 1
Chapter 1
Study
1
Question
Pair of Elements
Answer
To compel a body to move in a definite path, it must be paired with another , the shape of which is determined by the nature of the relative motion of two bodies.
2
Question
Mechanism
Answer
Combination of rigid bodies so arranged that the motion of one compels the motion of others, according to a law depending on the nature of combination.
3
Question
Machine
Answer
A combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to produce some effect or work accompanied with certain determinate motions.
4
Question
Constructive Mechanism
Answer
Calculates the forces acting on different parts of the machine, selects materials for strength and durability, considers repair and manufacturability
5
Question
Incomplete Pair
Answer
Formed when the reciprocal restraint of two elements is complete; that is, that each of the two bodies, by the rigidity of its material and the form given to it, restrained the other.
6
Question
Pure Mechanism or Kinematics of Machines
Answer
Treats the motion and forms of the parts of a machine and how they are supported and guided, independent of their strength
7
Question
Rigid Body
Answer
Body whose component particles remain at a constant distance from one another
8
Question
Frame
Answer
Structure that supports moving parts and regulates their motion in a machine
9
Question
Structure
Answer
A combination of resistant bodies capable of transmitting forces or carrying loads but having relative motion between parts.
10
Question
Closed or Lower Pair
Answer
If one element not only forms the envelope of the other, but also encloses it, the forms of the elements being geometrically identical, the one being solid or full, and the other being hallow or open
11
Question
Inversion of Pairs
Answer
The absolute motion of the moving piece is the same, whichever piece is fixed.
12
Question
Particle
Answer
Infinitesimal part of a body represented by a point
13
Question
Modes of Transmission
Answer
If the action of natural forces of attraction and repulsion is not considered, one piece cannot move another unless the two are in contact or are connected to each other by some intervening body that is capable of communicating the motion by the one to the other.
14
Question
Follower
Answer
Piece of a mechanism whose motion is effected
15
Question
Science of Mechanism
Answer
The laws governing the motion of the parts of a machine and the forces transmitted by these parts
16
Question
Driver
Answer
Piece of a mechanism that causes motion
17
Question
Higher Pair
Answer
Formed when the elements are in point or line contact and do not enclose each other.
18
Question
Bearings
Answer
Surfaces of contact between two pieces with relative motion
19
Question
Stationary bearing
Answer
Bearing where one piece is stationary
20
Question
Moving bearing
Answer
Bearing where both pieces are moving
21
Question
Collars
Answer
It is very often required that pulleys or wheels turn freely on their cylindrical shafts and at the same time have no motion along them
22
Question
Keys
Answer
Sometimes pulleys or couplings must be free to slide along their shafts but at the same time must turn with them, they must then be changed to a sliding pair
23
Question
Crank
Answer
An arm rotating or oscillating about an axis
24
Question
Lever
Answer
The combination particularly when the motion is oscillating over a relatively small angle
25
Question
Action of a Crank
Answer
A crank may be considered as a rigid piece connecting one member of a pair of cylindrical elements to one member of another pair
26
Question
Link
Answer
A rigid piece or a non elastic substance which serves to transmit force from one piece to another or to cause or control motion
27
Question
Linkage
Answer
It consists of a number of pairs of elements connected by links
28
Question
Four bar Linkage
Answer
A mechanism consisting of two cranks and two connecting rods connected to each other by a rigid rod or bar called the connecting rod coupler or floating link
Untitled Flashcards
Study
1
Question
223 Centripetal Force
Answer
The force that keeps an object moving in a circular path. It is directed towards the center of the circle and is responsible for constantly changing the direction of motion.
2
Question
216 Angular Speed
Answer
The time rate of turning of a body about an axis or the rate at which a line on a revolving body is changing direction and is expressed in angular units per unit of time.
3
Question
217 Uniform and Variable Speed
Answer
Speed is uniform when equal spaces are passed over in equal times, however small the intervals into which the time is divided. Speed is variable when unequal spaces are passed over in equal intervals of time.
4
Question
218 Velocity
Answer
A word often used synonymously with speed, but it includes direction and sense as well as speed. The linear velocity of a point is not fully defined unless the direction and sense in which it is moving and the rate at which it is moving are known.
5
Question
219 Linear Acceleration
Answer
The time rate of change of linear velocity. Acceleration may involve a change in speed or direction or both. Acceleration may be either positive or negative.
6
Question
220 Angular Acceleration
Answer
The time rate of change of angular velocity. Angular acceleration can involve a change in either speed or direction of rotation or both.
7
Question
221 Translation
Answer
Motion of a body when all its component particles have the same velocity as regards both speed and direction. It can be either rectilinear or curvilinear.
8
Question
222 Turning Bodies
Answer
All motion consists of translation, turning about an axis, or a combination of the two. Turning bodies refer to objects that are rotating about an axis.